Persistent Symptoms and Sequelae After Severe Acute Respiratory Syndrome Coronavirus 2 Infection Not Requiring Hospitalization: Results From Testing Denmark, a Danish Cross-sectional Survey

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is associated with persistent symptoms (“long COVID”). We assessed the burden of long COVID among nonhospitalized adults with polymerase chain reaction (PCR)–confirmed SARS-CoV-2 infection. METHODS: In the fall of 2020, a cross-sectional survey was performed in the adult Danish general population. This included a self-administered point-of-care test for SARS-CoV-2 antibodies, the Short Form Health Survey (SF-12), and coronavirus disease 2019 (COVID-19)–associated symptom questions. Nonhospitalized respondents with a positive SARS-CoV-2 PCR test ≥12 weeks before the survey (cases) were matched (1:10) to seronegative controls on age, sex, and body mass index. Propensity score–weighted odds ratios (ORs) and ORs for risk factors were estimated for each health outcome. RESULTS: In total, 742 cases and 7420 controls were included. The attributable risk of at least 1 long-COVID symptom was 25.0 per 100 cases (95% confidence interval [CI], 22.2–27.4). Compared to controls, cases reported worse general health (OR, 5.9 [95% CI, 5.0–7.0]) and had higher odds for a broad range of symptoms, particularly loss of taste (OR, 11.8 [95% CI, 9.5–14.6]) and smell (OR, 11.2 [95% CI, 9.1–13.9]). Physical and Mental Component Summary scores were also significantly reduced with differences of −2.5 (95% CI, −3.1 to −1.8) and −2.0 (95% CI, −2.7 to −1.2), respectively. Female sex and severity of initial infection were major risk factors for long COVID. CONCLUSIONS: Nonhospitalized SARS-CoV-2 PCR–positive individuals had significantly reduced physical and mental health, and 1 in 4 reported persistence of at least 1 long-COVID symptom.